Hampshire, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.8 °C (low) to 14.7 °C (high). Annual precipitation averages 979.2 Millimeters. Hampshire is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.2 °C | -1.5 °C | 46.23 mm |
| February | -8.4 °C | 1.1 °C | 45.72 mm |
| March | -3.1 °C | 7.6 °C | 57.66 mm |
| April | 2.6 °C | 14.9 °C | 93.98 mm |
| May | 8.9 °C | 21.3 °C | 125.48 mm |
| June | 14.4 °C | 26.6 °C | 121.41 mm |
| July | 16.8 °C | 28.6 °C | 99.82 mm |
| August | 15.8 °C | 27.4 °C | 103.12 mm |
| September | 11.3 °C | 23.8 °C | 89.66 mm |
| October | 4.9 °C | 16.7 °C | 79.76 mm |
| November | -1.1 °C | 8.5 °C | 63.25 mm |
| December | -6.8 °C | 1.4 °C | 53.09 mm |
| Annual | 3.8 °C | 14.7 °C | 979.18 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |